PSY 200 2.3

Fill in the blanks with the terms independent or dependent.

In experimental research, the researcher actively manipulates the environment to observe its effects on behavior.  The aspect of the environment that is manipulated is called the _____ variable; the behavior of interest is measured by the ______ variable.  To draw conclusions about cause and effect, the experimenter must make certain that the ________ variable is the only thing changing systematically in the environment.

Javier wants to determine whether the presence of Tom Cruise in a movie increases the box office take.  He randomly forms two groups of subjects.   One group sees Mission Impossible III, starring Cruise, and the other group sees Barney's Big Adventure, without Cruise.  Sure enough, the Tom Cruise movie is later rated as more enjoyable than the movie starring the purple dinosaur.  Javier concludes that Tom Cruise movies are sure winners.  What's wrong with this experiment?

a.  The dependent variable--Tom Cruise versus Barney--is confounded with the content of the movie.

b.  the independent variable--Tom Cruise versus Barney---is not the only factor changing across groups.

c.  Nothing has been manipulated---its really a correlational study.

d.  Experiments of this type require independent variables with at least three conditions.

Random assignment is an important research tool because it helps the researcher control for potential confounding variables.  Which of the following statements about random assignment is true?  Random assignment...
a.  eliminates individual differences among people

b.  ensures that some participants will get the experimental treatment and others will not.

c.  increases the likelihood that subject differences will be equally represented in each group.

d. controls for bias by ensured that biased subjects will be placed in the control group.